Roofing Shingles prices are calculated for MATERIALS ONLY. We use a 30-year type Architectural Asphalt Shingles material, and include all necessary accessories and flashing. Waste is calculated at 7.5% for a gable roof, and 15% for a hip roof, which are typical in the roofing industry.

Getting an Accurate Calculation

To properly calculate the amount of shingles and accessories needed for the job, follow the simple steps outlined below:

Step 1: Measure your roof accurately.

Use a measuring tape (preferably 50 or 100 feet long), and get exact ground dimensions of your house. Place the end hook of the tape on the corner and run it all the way to the opposite corner of the house. Measure both the WIDTH (gable side) and the LENGTH (eave / gutter side).

NOTE: If your house has a HIP roof, than it does not matter which side is the LENGTH and which is the WIDTH for accurate calculation. This is only important for gable roofs, as the calculator uses a specific formula to estimate roof run (length of gable). See the diagram below:

Step 2: Add overhangs to your roof.

If you have overhangs on the front, back and sides of your house (you most likely do), take the width of the overhang, multiply it by 2, and add to each side.

If the overhangs are not equal width, apply appropriate overhang width * 2, to the respective roof side.

To calculate the slope of your roof based on degrees, roof rise or X inches per 12″ run, use our Roof Pitch Calculator.

Otherwise, use the table or the roof slope diagram below:

Steep Slope – Roof pitch of 12 or 45 degrees.

Medium Steep Slope – Roof Pitch of 9

Medium Slope – Roof Pitch of 6

Medium Low Slope – Roof Pitch of 3 or 4

Note that if your roof is low slope (below 3 pitch) asphalt shingles are NOT the right material for it. You will need some type of rolled or single ply material, such as Rubber, Rolled Modified Roofing, Rolled Asphalt, or TPO / PVC membrane (best choice, but expensive).

We have added a specialty Metal Roofing Calculator, which will provide installation prices for the most common types of metal roofs, as well as estimate roof life expectancy and Cool Roof energy savings.

This is a pretty good estimator. Expect to pay in the high end of the $5.43 – $7.05 per square foot range for a licensed, bonded and insured contractor and for complex or rush projects. Hire carefully, only after verifying prior work quality.

For the best value on Shingle Roofing Installation: combine related projects; get bids from several pros; and be flexible about project scheduling.

Be prudent. Use all your good sense and judgment when dealing with insurance companies, adjusters, and contractors. Be as cautious as you would be for any other major purchase.

Prices are for GAF Timberline Lifetime (former 30 years) architectural shingles, and were sourced from Home Depot as well as 3 major roofing supply places in Boston. The results are an average of all 4 sources, and include shingles, underlay, drip edge, ice and water, ridge/hip caps, nails, flashing, ridge vent, caulk, etc … basically all the components of a complete system – as if you were installing a “warranty” job covered by GAF.